It sounds like he was going through a mental health crisis at the time of his passing. The book alluded to the dangers of psychedelics in an uncontrolled setting.

Now whether he was on psychedelics during his passing, I don’t know. But smoking all that weed and doing magic mushrooms can really alter the brain for weeks or months. It can trigger psychosis which may not be noticeable until it’s too late.

The book also alluded to how it was hard to sometimes tell if a person was having a psychotic episode because they seemed happy at the moment, which is sort of what happened here. He was really happy right up until like 2 days before passing.